Apparatus for manufacturing iron and steel.



No. 642,433. Patented Ian. 30, I900.

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APPARATUS FOR MANUFACTURING IRON AND STEEL.

(Application filed May 21, 1898.)

(No Model.)

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UNITED STATES PATENT OFFICE.

THOMAS DOHERTY, OF SARNIA, CANADA.

APPARATUS FOR MANUFACTURING IRON AND STEEL;

SPECIFICATION forming part of Letters Patent No. 642,433, dated January30, 1900.

Application filed May 21, 1898. Serial No. 681,273. lllo model.)

To all whom it may concern:

Be it known that I, THOMAS DOHERTY, a subject of the Queen of GreatBritain, residing at Sarnia, county of Lambton, Province of Ontario,Canada, have invented a certain new and useful Improvement in Apparatusfor Manufacturing Iron and Steel; and I declare the following to be afull, clear, and exact description of the invention, such as will enableothers skilled in the art to which it pertains to make and use the same,reference being had to the accompanying drawings, which form a part ofthis specification.

My invention relates to the manufacture of steel or semisteel frompig-iron or its equivalent in the same cupola in which the iron is firstmelted and in such wise that, if desired, the cupola can also be usedsimply for melting iron without converting the same into steel, wherebycastings of cast-iron or of steel or semisteel can be produced from thesame charge; and it consists in the apparatus herein described andclaimed.

Figure 1 is a sectional view of the cupola constructed and arranged insuch a way as to allow the employment of my process. Fig. 2 is adetailed figure of the twyer in perspective. Fig. 3 is a sectional View,broken away in the center to show a modification in the position of thetwyer. Fig. 4 is a vertical longitudinal section of the twyer and aportion of the airblast pipe, showing the swivel connection between thetwo.

In the drawings, A is the shell of the cupola, resting upon the base A,and which is lined, as is usual, with ordinary fire-brick B. l

O is the charge-door; D, the floor, which is arranged to be dropped inthe usual manner and which need not be described.

E is the tap-hole; D, the twyer; F, the airblast pipe, which isconnected to any appropriate air-blast apparatus. Above the twyer Iplace a thick partition of fire-brick H, molded to fit, which partitionhas a central perforation J. The partition H is concave on both theupper and lower faces, as this adds very much to the strength and also(on the upper face) facilitates the discharge of the molten metal.

K K are twyers above the partition, allowing for the introduction of airdirectly into the charge locatedabove the partition, if desired.

M is an orifice for the delivery of the molten slag, leading from thesubchamber below the partition H, and is arranged so that it issubstantially on a level with the orifice through the shell andfire-brick, into which the twyer D enters, and on a level with thehighest point that the twyer D can be raised in its adjustment. Thisrelative position is important in that it must not be above the twyerwhen raised, although it can be somewhat below it. The twyer properconsists of a casing N,within which a cylinder N is allowed to rock,being controlled by the handle N The cylinder carries a broad lip P,extending out through an orifice in its face, and when the casing is setinto the casing of a cupola this lip extends inward into the lowerchamber, as shown in Fig. 1. Opposite to the controlled end car ryingthe lever N an extension of the cylinder is connected by aswivel-coupling P to the blast-pipe F. This allows the broad lip P to beraised or lowered when inside of the cupola in the manner shown in Figs.1 and 3. The lip is perforated wit-h orifices R R R, which, extending tothe air-chamber in the casing, form a combination-twyer through whichthe air is blown into the cupola. As the twyer is arranged so that itcan be tilted, the inner end thereof, in which are located the orificesR R R, can be brought on a level with the slag-opening M or depressed soas to be below said opening, so that the blast can be thrownhorizontally or downwardly.

In carrying out my invention I place above the partition H, through thecharge-door, an ordinary charge of pig-iron or scrap-iron, or both, anda flux, in the usual manner, the charge resting upon the partition II.This charge is lighted, the air-blast turned on through the twyer D,and, if desired, to be assisted through the twyers K K. As the ironmelts it passes down through the central perforation J upon the floor ofthe cupola, being subjected more or less to the air-blast in descending,until it rises up to a level of the slag-hole M, which has heretoforebeen stopped. The slag-hole M is opened, the resistance of the passageof air through the orifice J and the charge above diverts the blastthrough the orifice M, carrying out with it the slag, which floats withthe surface of the molten metal, as shown at S in Fig. 1. As

the slag-hole is opposite to the twyer D, the effect, especially whenthe blast is directly across the surface of the molten iron, is to keepthe surface entirely free from slag, so that the descending metal fromthe upper chamber of the cupola does not carry with it any impurematerial. The same effect also takes place when the air is blown intothe body of the metal, as shown in Fig. 1, but in a somewhat lessdegree, as the air rises through the body of the metal, burning out thecarbon to a certain extent, also taking the direction of the slag-hole,carrying out the slag with it.

By manipulating the apparatusto the proper degree and the proper extent,as above described, I can obtain from it a very pure and fine grain ofcast-iron, free from impurities of any degree of decarbonized cast-iron,through all of the combinations of carbon to mild steel, thus enablingone and the same cupola to deliver practically any required quality ofmetal that may be desired in making diiferent castings from the sameheat.

I am aware that cupolas with subcham bers or converting-chambers havebeen heretofore described in various patents and publications and haveattempted to be used, but without much (if any) success. In these,however, there was no efficient means of getting rid of the slag andpreventingits admixture with the descending molten iron. Attempts havebeen made to do this by placing the slag-pipe in the upper portion ofthe converting-chamber and above the twyer. This, by experiment, I havefound will not answer and will not prevent the admixture of more or lessslag with the metal in the converter. I do not, there fore, broadlyclaim a cupola mounted upon a converter in direct communicationtherewith and provided with twyers.

What I claim is 1. The combination With a converter of rockable twyerssituated at one side of and extending into the interior of saidconverter, means for rocking said twyers, and a slagopening opposite theends of said twyers when at their highest point, the said twyers beingadapted to be rocked to direct a blast to the slag-openin g or at anypoint below said slag-opening, as set forth.

2. The combination, with a cupola and a converter in communication witheach other, the former above the latter, of rockable twyers situated atone side of and extending down'into the interior of said converter,means for rocking said twyers, and a slag-opening opposite said twyers,so arranged that the bottom thereof will be approximately on a levelwith the twyers at the highest point of their movement and above thelevel of the lowest point of their movement, whereby airblasts may bedirected over the surface of the molten metal to free it of slag, andthrough the body of the same to free it of carbon, as set forth.

In testimony whereof I sign this specification in the presence of twowitnesses.

THOMAS DOHERTY.

\Vitnesses:

JOHN GoWAN, OAMBY F. NEWELL.

